ATAC - Pharmacokinetics (PK) Sub-Protocol

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00784862
Recruitment Status : Completed
First Posted : November 4, 2008
Last Update Posted : May 15, 2009
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Brief Summary:
To assess the effect of ARIMIDEX on the pharmacokinetics of tamoxifen and the effects of tamoxifen on the pharmacokinetics of ARIMIDEX..

Condition or disease Intervention/treatment Phase
Breast Cancer Drug: Anastrozole Drug: Tamoxifen Phase 3

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 9358 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: A Randomised, Double Blind Trial to Assess the Pharmacokinetics of Arimidex Alone, Nolvadex Alone, or Arimidex and Nolvadex in Combination, When Used as Adjuvant Treatment for Breast Cancer in Postmenopausal Women
Study Start Date : June 1998
Actual Study Completion Date : March 1999

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U.S. FDA Resources

Arm Intervention/treatment
Active Comparator: 1
Arimidex 1mg + Nolvadex placebo
Drug: Anastrozole
1mg, orally, once daily
Other Name: Arimidex
Active Comparator: 2
Arimidex placebo + Nolvadex 20mg
Drug: Anastrozole
1mg, orally, once daily
Other Name: Arimidex
Drug: Tamoxifen
20mg, orally, once daily
Other Name: Nolvadex
Active Comparator: 3
Arimidex 1mg + Nolvadex 20mg
Drug: Tamoxifen
20mg, orally, once daily
Other Name: Nolvadex

Primary Outcome Measures :
  1. Steady state plasma trough concentrations of tamoxifen, desmethyltamoxifen and anastrozole [ Time Frame: 24±4 hours after previous dose ]

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Ages Eligible for Study:   45 Years and older   (Adult, Senior)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Eligible for entry into the main ATAC trial 1033IL/0029
  • Patients must have been taking ATAC trial medication for at least 3 months (i.e. patients must have reached at least visit 2 of the main ATAC study)
  • Patients should be taking their medication in the mornings for at least 3 months
  • Patients must be 100% compliant over the preceding fourteen days

Exclusion Criteria:

  • Excluded from entry into the main ATAC trial (1033IL/0029)
  • Patients whose concurrent treatment includes diazepam or drugs which might affect tamoxifen steady state levels or steroid hormone status. These include ketoconazole (antifungal) or related compounds

Responsible Party: Francisco Sapunar, Medical Science Director, Arimidex and Faslodex, AstraZeneca Pharmaceuticals Identifier: NCT00784862     History of Changes
Other Study ID Numbers: 1033IA/0029
First Posted: November 4, 2008    Key Record Dates
Last Update Posted: May 15, 2009
Last Verified: May 2009

Additional relevant MeSH terms:
Breast Neoplasms
Neoplasms by Site
Breast Diseases
Skin Diseases
Estrogen Antagonists
Hormone Antagonists
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs
Antineoplastic Agents, Hormonal
Antineoplastic Agents
Selective Estrogen Receptor Modulators
Estrogen Receptor Modulators
Bone Density Conservation Agents
Aromatase Inhibitors
Steroid Synthesis Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action